'The Blind Side': Making This Season's Surprise Box Office Smash Hit

"I was ecstatic about the whole thing," he said. "I was mainly like, 'Oh, now, man, I hope they like me, I hope when they see me, they just say, you know, we're making you Michael.'"

But Aaron knew that despite his hopes, his chances were slim to none.

Hancock says that after their meeting, "[Aaron] reached in his wallet and pulled...out a card, and he said, 'I know this is the longest of long shots, that I'm probably not going to get this movie, but I do security guard work, and if you guys need a security guard on the set, I would love the job, and I need the job.' I took the card and I said, 'I'll keep that in mind, Quinton. I'll be in touch.'"

A year would pass before casting was complete, and in that time, Aaron's life spiraled downward. His mother died. He couldn't pay his rent. Like the real Michael Oher had been, Aaron was in dire straits.

"We didn't have lights, we didn't have money for food...," Aaron said. "And I just kept telling myself I know something's gonna come up... I just kept believing that."

Quinton Aaron Gets Big Break

Just days before he was to be evicted, the phone finally rang. Aaron got the part.

"It was unexplainable, but it was like my heart was pounding. I almost teared up a little bit, you know, but it was cool 'cause it -- it's something I was waiting on for such a long time," he said.

The first step for Aaron would be a physical transformation. "This was a role that I would have done anything for. And I kind of proved this by losing 100 pounds in three months," he said. "You know, I was determined to do -- anything I could to be the perfect guy they needed for the role."

Emotionally, Aaron was already in touch with his character's dramatic arc.

"He and Michael [Oher] had things in common," Hancock said. "They were on a parallel track in many ways. From an actor standpoint, he gets to draw on some of those feelings, and perhaps that's why they seem so real in the movie."

Oher on Movie Portrayal

While their home situations may have drawn some similarities, one would think from watching the movie that their early athletic abilities also had parallels.

"In the movie, when they showed me the...practice scenes," said Aaron, " and [Michael] doesn't really know what to do, he's doing everything wrong, it's a lot like how I was on the football field, which is why I didn't follow a career in football...I was bad. "

But Oher told "20/20" that the way the movie portrayed his early athletic ability wasn't on point.

"It wasn't like that...I've always known how to play football," Oher said. "You know, it's Hollywood...that's what they do. But...at the end of the day, it's still a....good story."

Sean Tuohy, Oher's adoptive father, who also understands the responsibility of Hollywood, thinks the story about him and his family has been portrayed well.

"You have to take liberties in a movie, and truth is, if a movie isn't entertaining, people won't go to see it," he said.

There is "an added responsibility when the people you're portraying are alive... you owe them kind of, as honest a portrayal as you can," Hancock told "20/20."

And although Hancock said "Job one is to tell a story that entertains," he is pleased that some audience members have been inspired by the story.

"The movie was never made to be a call to arms in any way for charity ," said Hancock, "but as a byproduct, it's a pretty nice one to have."